I thought there was insurance cover over your room in DC as standard... either way, what type of room have you got? Because I was in block D last year (new room with sink) and all doors into the building have codes and the individual rooms' doors are key locked and are secure. Only be concerned if you're on the ground floor where the window could be a possible entry point. Higher floors are impossible to climb into (I should think, I haven't actually tried)
Have you been tested?